Structural Live Load for a Sidewalk 4

[dik]

If you have a structual concrete slab that is used for a sidewalk, what sort of live load would most of you use? Like small snow clearing equipment at most... say 250 psf? I've done similar situations where garbage trucks are common and usually use 400 to 500 psf (actual wheel loads have been checked). Any suggestions appreciated. Thanks.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[SlideRuleEra]

dik - The current New York City Building Code has this requirement:

All sidewalks and driveways or portions thereof that are structurally supported shall be designed for a live load of one hundred psf uniformly distributed and in accordance with the provisions of subchapter ten of this chapter. Where subject to intentionally or accidentally imposed wheel loads of vehicles, such portions of sidewalks and driveways shall be designed for a uniformly distributed load of six hundred psf or for the maximum vehicular wheel load that could be imposed thereon, whichever develops the greater stresses.

 

[dik]

thanks SRE... I'll check with the City on Monday to see if they have a recommendation or requirement. I've done a few with garbage trucks (they are about the heaviest) and they come out to an equivalent 400 or 500 psf... not near 600, though. Maybe NYC has heavier garbage? Again, thanks.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dhengr]

Dik:
The heaviest, fairly common vehicle, is probably a Fire Dept. tanker/pumper, and they do expect private drives and bridges to accommodate these. I don’t know the wheel loads off the top of my head.

 

[dik]

Thanks dhengr... A firetruck would not be able to access this space. At each end of the slab area the buiding extends out to the width of the slab. at most a small skidsteer type of plow could access the space. I'm not sure a snow clearing vehicle could drive on it and load it. They are generally pretty small.

I think a garbage truck has a higher wheel load than a firetruck, but I will check. A garbage truck would not be able to access the area either. The existing drawings are not available and the actual existing construction cannot be determined. I've never seen a buiding extend out to include part of the public sidewalk, or the space is wider at the I think the construction is 12 HC, waterproofing membrane, rigid insulation, concrete sidewalk slab, and no protection board, but I'm not sure. The The damage has already been done, and I'm going to be effecting a repair.

The existing structure is 12" HC extending outside the building by about 2 feet and forms part of the public sidewalk. The contractor cut through the HC, cutting some strand, not realising/knowing the materials of construcion, and I have to provide a permanent support for the 'interrupted' HC slab. I would never have guessed the support was HC. The exterior wall forms part of this 30" space. It's not possible for any type of vehicle to park on it and have the wheel loading on the slab... It's essentially recessed into the building space. The attached plan is something similar to what I'm looking at.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[milkshakelake]

I'd use 100 psf for the sidewalk because a fire truck would not be able to get on top of it (I use the NYC code myself). The 600 psf number is based on a fire truck loading because the same number shows up in the fire code. My interpretation is that the 600 psf is for the actual road, so 100 psf for the HC slab should be fine. Not related to you, but this also results in a simplification we use for lateral loading, which is 300 psf surcharge because the road is generally far away from the foundation wall.

 

[dik]

Thanks... I was going to run with 250, but 100 seems a little more realistic. I'll check with the city tomorrow to see if they have any requirements.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[TLHS]

Dik, I am not in a place where I can look at it for a few days but I'm pretty sure there's at least something on this in CSA S-6 including discussion of small vehicle loads. Not a hundred percent but I can picture a load diagram including sidewalks.

 

[TLHS]

Oh, and on the subject of buildings extending under the sidewalk, there's a part of downtown Vancouver where it was pretty typical and back in the day they used glass brick in the sidewalk to let light in. There are still a handful in place.

I understand this was typical in a few places in the western US too.

https://scoutmagazine.ca/2018/04/30/hunting-vancouvers-forgotten-sidewalk-prisms/

 

[JLNJ]

The point load from an actual wheel seems like it would control over a distributed load, even for a relatively narrow section of walk.

 

[dik]

Thanks JL... but, it would be difficult to get a wheel onto the space... I'll check it for a point load. I have to design some steel framing to support the HC slab...

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

Thanks TL... I've got a copy of S6... I'll take a gander.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[CrabbyT]

ASCE 7-10 requires a 250 psf area live load or an 8000 lb concentrated live load over a 4.5" × 4.5" area for sidewalks, vehicular driveways, and yards subject to trucking

 

[dik]

Thanks, Crabby... I put a call into the plan examiner at the city, and we'll see what shakes loose...

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[TLHS]

This is likely very moot at this point, but I was hanging out in the clauses following the loading tables in the NBCC and realized that it discusses this. If it doesn't help you, I know it'll help me next time I need to do this and I remember there was a thread about it.

I'm referencing NBCC 2015.

Table 4.1.5.3

So your minimums look like they're 12kPa for vehicles, 4.8kPa (or snow) if it's only pedestrian accessible. Then there's point loads in the next table.

The appendix reference says that you should do a study for loads over areaways and basements, and to reference S16 if appropriate.

The comedy option is obviously to install a bench and set up a busking area so that you can declare the sidewalk assembly area a theatre with fixed seats and reduce your live load.

 

[dik]

Thanks THLS... I decided to use 250psf. The query I sent in to the city hasn't been answered. It's only possible for small slow clearing equipment to even get somewhat close to the area. I'm still trying to obtain structural drawings for the project to confirm construction. The slab forms part of the city sidewalk and from the 'damage' done, it appears to be 12" HC. The problem is a matter of supporting the 'broken' parts of the HC Slab... the opening was near mid span. It's an odd situation; I would not have expected to find HC slab in that location... and, I guess the electrical contractor didn't either.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik